This invention relates to coupling arrangements for a pair of tubes particularly of the type wherein one tube is adapted to telescopically slide into the end of another tube, and the invention is particularly concerned with the provision of such a device for the suction tubes of a vacuum cleaner wherein the tubes must be adapted to be readily and simply connected and disconnected.
Coupling arrangements of the above type are generally known. In one type of coupling, for example, and outer suction tube is provided with a hole spaced from one end thereof, and a lip extending outwardly from the open end to enable the guiding of a button toward the hole. In this arrangement, the inner of the tubes also has a hole, which is alignable with the hole of the outer tube. A button is resiliently held in the hole of the inner tube, so that the button may be aligned with the lip of the outer tube and rapidly directed into locking position to extend through the hole of the outer tube. In this arrangement, the spring for resiliently holding the button consists of a simple leaf spring affixed at one end to the inside of the inner tube, and affixed at the other end to the inside end of the button.
With the above arrangement, a stop, generally in the form of an indentation, is provided in the outer tube in order to inhibit the forcing of the inner tube into the outer tube to positions beyond which the two holes are aligned. In structures of this type it was considered necessary to provide this alignment stop, since the tubes are generally assembled rapidly without particular attention being paid to the relative alignment of the two holes.
The above known arrangement has the further disadvantage that the relative positioning of the holes, latch and stop present some tolerance problems in the production of the structure. In addition, such arrangements generally are limited to the provision of a relatively short spring which has limited flex life.